There is now overwhelming evidence that heredity can play a significant role in an individual's risk of a variety of illnesses, including cancer. One compelling example is breast cancer. Healthy women with a history of breast cancer in one or more first degree relatives are now widely known to be at increased risk of developing the disease themselves. The vast majority of women who have family histories of breast cancer must thus live with the threat that their health and even life may be claimed at any time. The psychological reactions of women to that threat may result in additional risks to their health through at least two basic pathways: 1) high levels of fear/distress may inhibit appropriate breast cancer screening behaviors, resulting in late detection and reduced likelihood of curative treatment; and 2) high levels of distress may have biological consequences, resulting in compromised bodily defenses against various pathogenic challenges. The goal of the proposed research is to investigate the possibility that having a family history of breast cancer is a stressor that may have adverse psychological and biological consequences, and that fear/distress about breast cancer may interfere with screening behaviors. In addition, we propose to examine the possibility that these consequences may be more severe in black women, for whom the fear of developing breast cancer may be especially high.